Field of the Invention
The invention relates to a walking mechanism for draglines. Discussion of Prior Art
A walking dragline typically includes a main housing and a boom which extends upwardly and outwardly from the main housing and has thereon a sheave for supporting a hoist rope. The hoist rope extends from a bucket hoist mechanism and over the sheave to a bucket for causing vertical movement of the bucket. A drag rope extends between a bucket drag mechanism and the bucket for causing horizontal movement of the bucket. The main housing is supported by a tub that sits on the ground when the dragline is engaged in digging operations. A pair of walking mechanisms are mounted on the opposite sides of the main housing and are operable for moving the main housing over the ground between digging operations. An overhead crane is mounted in the interior of the main housing for lifting and moving components for repairs.
U.S. Pat. No. 5,245,882 discloses a walking mechanism of ordinary construction. A walking mechanism ordinarily includes a shoe for engaging the ground during walking movement. The shoe is fixed to a walk leg housing which is mounted on an eccentric and which is connected by a knee link to the main housing, such that rotation of the eccentric causes the walk leg housing to pivot, thereby causing walking movement of the shoe. The eccentric is fixed to a main walk shaft and rotates at about one revolution per minute. The main walk shaft is driven by a large diameter driven gear which is spline fit to the main walk shaft. The driven gear is driven by an output pinion mounted on the output shaft of a large gear box. The gear box is driven by a large motor.